Leon 1.9Tdi Problem

[richieboy077]

Hi All,

Some of you may already know me but i posted a thread about a month ago regarding problems with my car. Basicaly i was told the car was going into limp mode and to get it done on vag com. Ive had this done and no codes came up atoll with no history of problems ever on this vehicle. So im after some help, right the car was recently serviced and i told the guy these probs i was getting with car seeming laggy and in 4th overtaking the car was like hitting a brick wall and not going no where, turbo loss. With this he changed the fuel filter as you can see air bubble flowing through the clear pipe(is this normal), this is still happening could this be the problem with turbo loss?, also told the mass air flow sensor could be at its end and need replacing, could this be the problem?, and the worst thing ive been told is the turbo could be going, this is not what i wont to hear. If any one could help me it would be much apreciated. The car is at 100k, year 2003.

Many thanks

Richie

 

[richieboy077]

Anyone?,

Can any explain the air bubbles flowing through the clear pipe off the fuel filter?.

Thanks

Richie

 

[CupraRmark]

are you sure the air bubbles is the feed pipe m8 or the return pipe, i wouldnt of thought the fuel is the issue like you said more like maf or turbo or actuator/wastegate fault .... if it was fuel you would probo get a very jurky build up but if you get smooth delivery id start turbo side

 

[allh2k]

Bubbles r normal

What engine is it?

Ive got a asv 110 n had limp mode since 100k now 120k its one of 3 to 4 things from most expensive n mostly the list is :-

Turbo needs replacing £500
Turbo just needs cleaning £50
Maf £40-70
N75 and other sensors

To diagnoise ur problem u need vagcom £10 off fleebay. This will allow to log ur maf n other sensors.

Get ur hands dirty try pushing ur actuator in n out i beleive it moves n inch or so, take a look at ur egr n cvv .

 

[Muttley]

Possibilities are MAF, turbo vanes, inlet manifold coked up and/or EGR valve sticking.

MAF is easy to test: unplug it, and if there is no change in the way the car behaves, then the MAF is shot. MAF problems often don't cause a fault code.

Turbo vanes is the most likely problem, the turbo gets sooted up and the vanes stick instead of opening at higher rpm. This has the effect of overboosting, the turbo is spinning too fast, and the car goes into limp mode to protect the engine. However, this should cause a fault code to be logged in the ECU.

In high-mileage engines the inlet manifold, downstream of the EGR valve, gets coated in spongy carbon deposits, caused by the hot sooty exhaust gas from the EGR mixing with the oily vapours in the inlet charge that are introduced by the crankcase breather further upstream. This can lead to significant narrowing of the manifold tubes, choking the engine. This is often accompanied by the EGR valve itself coking up and not closing at high revs like it's supposed to. This lets exhaust pressure into the inlet, which causes overboost. Again, this usually throws a fault code.

Small air bubbles in the fuel lines are not unusual - I have some - and are not usually a problem.

At 100K your turbo should not be anywhere near worn out unless previous owners have neglected the oil change intervals.

 

[richieboy077]

Thanks for all your help lads,

When it got done on vag com no faults were found, im going to change the maf i think. At first i Thougt it was only happening when the engine was cold, but coming home today whilst engine hot i was in 2nd gear up a large hill stuck at 20mph, had to pull over and switch engine off, started back up and drove on ok but laggy.

Richie

 

[richieboy077]

Just a update and in need of more help.

I have now changed the MAF, drove it after and it was fine, felt to me i had more acceleration and was flying up and down the bypass without a problem so i thought maybe i had cracked it by changing the MAF. To my horror driving home from work today i had to overtake, in 4th gear, i get to 60mph and dead car sitting at 60mph flat, no turbo/boost, had to pull over and switch engine off and start again. Please note the engine was still not warm and not at 90 in oil temp gauge. Im really f*** to what to do next?, Please help me.

Richie

 

[allh2k]

If its in limp mode maf reading stays at 550 so 15% throttle will give some acceleration

If ur engine isnt warm n ur over taking then ur gonna mess it up n unless i missed something the temp gauge is ur coolant n not oil the oil takes an extra 5-10 minutes when it does reach 90

Stop over taking slow down n get vagcom!

 

[richieboy077]

Problem is allh2k ive had it on vagcom and no faults came up?, and the mechanics have tried to get it to go into limp mode by booting it and they cant, but at first i thougt it was just happening when cold and coolant below 90 but it also now happens when at 90, when overtaking and when just needing that turbo to work for a wile not short intervals.

Im stuck now what todo for the best.

 

[krisby]

Can you hear the turbo whistle? I've been through it all too, been advised actuator, maf, fuses, turbo, but after much testing, cleaning, etc, have discovered my MAF is actually not receiving any power, so I need my wiring harness or plug replaced.

However, I do get an error, short to ground on the MAF, whereas you don't which is very odd to get limp mode and no errors.

Mine even went a bit weird for a while, no limp mode and was boosting like a petrol at 4000rpm, very un TDi like, however, that was short lived, after I noticed my air intake and southside of EGR were not connected properly.

 

[richieboy077]

The turbo doesnt whistle as such, but does make a whoosh noise changing from 1st to 2nd, 2nd to 3rd. If only a bloody code came up.

Richie

 

[aymen_a22]

Just wondering if you are still having this problem, I am having exactly the same problem and I have just been to a turbo specialist.

They advised me to check the following:
1) all the boost pipes
2) swap the N75 valves on the firewall (as they do the same thing apparently)
3) check the vacuum pipes

and if all this seems fine then it is the turbo.

The guy also said to look at the VNT actuator (on the turbo, you can see it when looking down behind the EGR) when the engine starts up a vacuum should be produced and the actuator should move smoothly.

I just tried this and the actuator moves however the engine is still going into limp mode if I boot it (usually after 3000 RPM). Maybe it is the MAF or a boost leak I have no idea.

Any more ideas???

 

[krisby]

Just wondering if you are still having this problem, I am having exactly the same problem and I have just been to a turbo specialist.

They advised me to check the following:
1) all the boost pipes
2) swap the N75 valves on the firewall (as they do the same thing apparently)
3) check the vacuum pipes

and if all this seems fine then it is the turbo.

The guy also said to look at the VNT actuator (on the turbo, you can see it when looking down behind the EGR) when the engine starts up a vacuum should be produced and the actuator should move smoothly.

I just tried this and the actuator moves however the engine is still going into limp mode if I boot it (usually after 3000 RPM). Maybe it is the MAF or a boost leak I have no idea.

Any more ideas???

Have you changed/checked the MAF?

I would also recommend cleaning the turbo, I got a can of some turbo clean stuff, not the one everyone raves about, some other one from Halfords, in a hurry so can't remember right now, but I put the whole can through and the amount of smoke that came out was staggering, I would say it definitely cleaned up my turbo, and allowed the vanes to open properly.

Sorry to rush reply, gotta feed my daughter before school disco.

 

[sssstew]

Just wondering if you are still having this problem, I am having exactly the same problem and I have just been to a turbo specialist.

They advised me to check the following:
1) all the boost pipes
2) swap the N75 valves on the firewall (as they do the same thing apparently)
3) check the vacuum pipes

and if all this seems fine then it is the turbo.

The guy also said to look at the VNT actuator (on the turbo, you can see it when looking down behind the EGR) when the engine starts up a vacuum should be produced and the actuator should move smoothly.

I just tried this and the actuator moves however the engine is still going into limp mode if I boot it (usually after 3000 RPM). Maybe it is the MAF or a boost leak I have no idea.

Any more ideas???

Get it on VAG COM/VCDS and let us know the error which is logged when it goes into limp.

Do all of the above steps, and clean up the turbo, either with innotec or drop off and clean up then report back to us....

 

[aymen_a22]

Right, I have just taken the MAF out and tried to clean it but didn't have any electrical contact cleaner so just sort of left it alone. I started the engine with the MAF unplugged and nothing was different and no lights came up on the dash, is this right?

I had her plugged in a couple of days ago and only got:
17965 Charge Pressure Control: Positive Deviation P1557

I don't have time to clean up the turbo at the moment however the actuator is moving on engine start up which makes me think the VNT system is operating as it should (unless I got lucky and it is intermittent.

When I have more time I will take the turbo off the car and dismantle it however I believe that means exhaust manifold off, down pipe off, oil lines off, EGR off, actuator vacuum line off then extract the turbo, does this sound right?

Any help would be great.

 

[sssstew]

yep sometimes the MAF doesnt log with a dash light. You should have noticed the difference (drop) in performance driving unplugged, did you?

Positive deviation is getting too much boost, the vanes get stuck and it cannot respond quick enough for the ECU which sees the higher boost still and then puts it into limp. Your going to need to either drop the turbo and clean or if you dont want to do all the dismantelling try the innotec first.

 

[sonnex22]

i had this, so i removed the egr and cleaned it out inside, since that was done (14k ago) no problems.

 

[krisby]

Yep, clean EGR, mine was filthy, though my butterfly was moving freely.

Just remembered too, I didn't use innotec, I got a can of 10k boost diesel cleaner from Halfords, IMO worked just as well, was blowing clean by the end of the can, and been great ever since, and only takes 10 minutes. My cousin having similar problems on his nissan almera 2.2dci, so I suggested he do the same, the cheapest and easiest option before you start dismantling stuff.

 

[richieboy077]

Hi,

Yeah i am still getting the exact same problem, taken it to garage again BUT this time they got it into limp mode and plugged into VAG COM and STILL no faults coming up on laptop?.

They now wont it for a couple of days to try differnt things ie. N75 valve etc. They at first told me my turbo is gone which i was amazed at as this is the first time a garage has told me this. Surley if my turbo is going/gone i would be losing oil and puffing black smoke evey day with no power, which im not and have boost. But i am now noticing more that my turbo sounds loud when spooling up and coming off the pedal, like a dump valve.

And for one reason or another the car is at its worst on start up and drive for the first 10mins. Also in my earlier posts i say about my temp gauge taking ages to to rise, quick chat with a mate and thermostat and coolant sensor changed and the temp is spot on.

Thanks

Richie

 

[krisby]

It will be worse when cold, the ECU is compensating and does not allow full boost until the engine is warm, I too found it was easier to get limp mode when the engine was cold.

Being a diesel they do also take longer to warm up, thicker heads and all that. But as you say, if not using oil then I would not suspect the turbo is gone. I too hear mine spooling up and going pfffish between gear changes, particularly noticeable when driving slowly and changing gear slowly.

Having been through a myriad of things on my car, my problem turned out to be a simple wire needed resoldering on the plug for the MAF, I hope in your case it is something small and cheap too.